Modernist Gwynne dies aged 90

As with many young architects from well-to-do families, Gwynne began with a commission to design his parents' house. Unlike other budding architects, he designed his first building with a clarity that was to make it perhaps the greatest achievement of a long career.

Homewood in Esher, Surrey, is celebrated for being an uncompromisingly rectilinear implantation of European modernism, in spite of the elongated house's woodland setting.

After the war Gwynne ran a small practice specialising in commissions for luxury homes and penthouses in London and the South-east. His clients included actor Jack Hawkins and hotelier Charles Forte. He also designed restaurants, including two service stations for Forte at Burtonwood, Lancashire, on the M62 and Leigh Delamere, Wiltshire, on the M4.

By the 1960s, Gwynne had developed a flamboyant style deployed prominently at the Serpentine restaurant in Hyde Park (demolished in 1990) and the front-of-house extension to York's Georgian Theatre Royal. Both buildings consisted nearly entirely of collections of hexagonal umbrella modules in precast concrete, assembled in irregular configurations to suit the sites and sheathed in window walls.

Gwynne continued to live and work in Homewood, which he bequeathed to the National Trust in 1993. The trust now hopes to open it to the public next year after refurbishment supervised by John Allen of Avanti Architects.